The role of LYVE-1⁺ macrophages in the development of squamous cell carcinoma of the head and neck

A characteristic of head and neck squamous cell carcinoma (HNSCC) is their high immune cell infiltrate. This consists, among other things, of macrophages (MΦ), which have a high degree of heterogeneity and diverse roles in tumor development. In the context of immunohistochemical studies on human HNSCCs, we observed MΦ, which express the lymphatic vessel endothelial hyaluronic acid receptor 1 (LYVE-1). These were mainly present in areas with muscles and blood vessels. In particular in the oncological context, these MΦ have not been characterized very much, but it is suggested that they are local MΦ with the potential to regulate vascular permeability, immune cell invasion and the perivascular collagen content. Since these processes also influence HNSCC development, we pursue the hypothesis that LYVE-1+ MΦ play a role in this. We expect that a changing number of these MΦ will promote tumor growth by promoting fibrosis and modulating the immune cell invasion. To clarify these hypotheses, we use multiplex immunohistochemistry to compare formalin-fixed, paraffin-embedded tissues from HNSCCs and controls. First results indicate differences in the cell density of LYVE-1+ MΦ between controls and HNSCCs. Furthermore, a protocol for the differentiation of LYVE-1+ MΦ in vitro for mechanistic investigations was set up and its phenotype was characterized. Using functional assays and RNAi, we check their ability to present antigens, activate T cells and regulate fibrosis. Transwellassays will provide information about the regulation of cell migration. So far, our observations suggest an affection of local MΦ by HNSCCs.

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Artikel online veröffentlicht:
24. Mai 2022